Installation
34
TT Twin-Screw Pump -
Installation, Operation & Maintenance Manual
When the reading
value is...
Then do this.
Negative
The coupling halves are farther apart on the right side than the left. To
correct this, do one of the following:
• Slide the DE of the driver to the left.
• Slide the NDE of the driver to the right.
Positive
The coupling halves are closer together on the right side than the left. To
correct this do one of the following:
• Slide the DE of the driver to the right.
• Slide the NDE of the driver to the left.
Figure 7 Example of incorrect horizontal alignment (top view)
Perform parallel alignment for a vertical correction
Refer to the "
Calculate the thermal expansion
" section for the proper cold alignment
value based on the driver temperature rise and the pump operating temperature.
Before you start this procedure, make sure that the dial indicators are correctly set up.
A unit is in parallel alignment when the parallel alignment indicator does not vary by
more than the table limits when measured at four points 90° apart at the operating
temperature.
NOTICE:
The specified misalignment values are valid only at operating temperature. For cold settings,
different values must be used to account for the expected thermal expansion. Failure to do so
can result in being unable to successfully perform hot alignment.
1. Set the parallel alignment indicator to zero at the top-
center position (12 o’clock) of
the driver coupling half.
2. Rotate the indicator to the bottom-
center position (6 o’clock).
3. Record the indicator reading.
4. Add or remove shims in equal amounts from under all driver feet.
5. Repeat the previous steps until the allowable reading value is achieved.
